Table 1
Covalent hapten-protein adducts and non-covalent drug-protein complexes
Covalent bonds between Non-Covalent bindings hapten and protein between
drug and protein (hapten protein adducts) (drug-protein
complexes)
stable Stability reversible
high affine Affinity low to medium affine
>20 min to hours Duration Very rapid < 5
min
Hapten protein adduct is as new Stimulation As labile
drug-carrier complex not antigen stimulatory for T and B cellsBehaviour stimulatory for B and T cells, but (IgE) may be able
to interact with
preformed IgE.
The slow formation and gradual MC- unresponsiveness The rapid
formation of increase of hapten-carrier protein complexes able to bind
to adducts allows induction of preformed drug-specific IgE (= fake
unresponsiveness of mast cells: antigens) may overcome MC-
No symptoms appear unresponsiveness and elicit MC degranulation with
symptoms of anaphylaxis.